[Cla]

Good morning,

I have a doubt. I have created two bodies linked by an interface, Is it possibile to generate the grid motion only for 1 body and, in the same time, the other body's node on the interface are fixed?

Thanks.

[vinerm]

That is the primary objective of having interfaces; to allow for a relative motion between two bodies. Do note although that the motion can only be tangential to the interface.

[Cla]

ok, thanks. Can the motion only tangential?
In other discussion I explained my problem about the interfaces.
I'm studying Wankel engine.
In geometry I have created a Wankel engine with two objects ( engine chamber and inlet/outlet pipes) and their interfaces.I was obliged to create two bodies (chamber and pipes) because only on the red lines the node grid udf is applied. For reducing the time calculation, I have written an udf to let the grid housing move. The problem occurs because the interfaceses move with housing and there isn't an update. I'd like the interface remains fixed in the space while the nodes can rotate and uptate their position as housing. Is it possibile ? Is there another solution?
Yellow lines in files are interfaces and the red lines
Thanks.

[vinerm]

Simulation of Wankel engine usually does not require an interface; actually, interfaces are used only with moving mesh problems, where the cell zones are moved tangentially along the interface. Motion of the piston in a Wankel engine is different. You should not use any interfaces at all. The fluid chamber whose shape is changing should be connected with the fluid zones external to it via interiors, but interfaces won't pose any problem either. In other words, interfaces have no effect on what you are doing. And you do not have any constraint on motion of the mesh since you are using dynamic mesh; constraint is only for mesh motion using cell zones. Usually, for Wankel engines and gear-pumps, 2.5D method is preferred since it maintains the quality of the mesh as well as continuity.